#include<bits/stdc++.h>
using namespace std;
int main(){
	int a[100]=0,n,i,f,e,d,c,b,w;
	cin>>n;
	for(i=1;i<=n;i++){
		cin>>a[i];
		if(a[i]<20){
			f=f+1;
		}else(a[i]<30||a[i]>19);{
			e=e+1;
		}else(a[i]<40||a[i]>29);{
			d=d+1;
		}else(a[i]<50||a[i]>39);{
			c=c+1;
		}else(a[i]<60||a[i]>49;){
			b=b+1;
		}else(a[i]>=60);{
			w=w+1;
		}
	}
	cout<<"E"<<":"<<e<<endl<<"F"<<":"<<f<<endl<<"C"<<":"<<c<<endl<<"B"<<":"<<b<<endl<<"D"<<":"<<d<<endl<<"A"<<":"<<w<<endl;
}
/**************************************************************
	Problem: 1314
	User: huxuanchen
	Language: C++
	Result: Compile Error
****************************************************************/